Hinge actuators are known and is used, for instance, as a hinge actuator for a wing mirror unit of a motor vehicle. The first part of the actuator is then typically connected with the door of a motor vehicle. The first part then often comprises a base plate to be mounted on the door, which base plate is provided with a basic shaft. The second part then comprises a mirror support, which is typically arranged pivotably about the basic shaft. The mirror support, also referred to as mirror supporting frame, typically comprises a mirror housing in which a mirror glass is accommodated.
The mirror support, in particular the mirror housing, can then pivot relative to the base plate between a folded-in position, in which the width of the vehicle, for instance for the purpose parking, is reduced, and a folded-out position for use of the wing mirror unit under normal operating conditions. In the folded-in position, the mirror support extends in substantially rearward orientation along the longitudinal axis of the bodywork of the vehicle. In the folded-out position, the mirror support extends substantially transversely to the longitudinal axis of the bodywork.
The folded-out position is then defined in that the stops cooperate upon outward pivoting in the first pivoting direction from the folded-in position to the folded-out position, so that further pivoting is hampered. Upon an overload in the outward pivoting direction, typically, the cooperating stops can be overcome, so that the mirror support can pivot beyond the folded-out position to an overfold position.
The mirror support can be pivoted both electrically and non-electrically, for instance manually, relative to the base plate. By the use of the coupling between the first and the second part, the electric drive can be uncoupled, so that a pivoting movement of the mirror support not caused by the drive, for instance an inward pivoting movement resulting from impact forces or a manual inward pivoting movement, does not force any movements of the drives. Thus, damage to the electric drive, such as fracture in the drive train or defects in an electric motor, can be avoided.
It is desired that the select or predetermined position of the actuator parts relative to each other be well-defined. In the use of the hinge actuator in a wing mirror unit, in this way for instance the folded-out position of the mirror support can then be defined so well that unintentional pivoting to the overfold position is prevented. In practice, the folded-out position in the first pivoting direction, i.e. in an outward pivoting direction towards the overfold position, is typically defined in that the stops are under spring action and cooperate with high friction. The definition of the select or predetermined position in the second, opposing or opposite direction, i.e. in an inward or backward pivoting direction from the folded-out position towards the folded-in position, is typically defined in that the drive is made of self-braking design.
It has been found desirable, however, that the mirror housing upon manual adjustment be secured in the folded-out position in such a way that a clearly sensible coupling or “click” can be felt. For instance, the force that is needed to pivot the mirror support from the folded-out position to the folded-in position is of the same order of magnitude as the required force for pivoting from the folded-out position to the overfold position. By providing a pair of auxiliary stops which, from the select or predetermined position, cooperate in the second pivoting direction, i.e., in the case of a wing mirror unit, from the folded-out position in the inward pivoting direction, this problem can be solved.
However, the force required for overcoming both the stops and the extra stops would have to be of the same order of magnitude. However, the electric drive then cannot adjust the mirror housing from the folded-out position to the folded-in position, unless unacceptably powerful and costly electric motors are used, or the force required for overcoming the extra stops is so slight that upon manual inward pivoting from the folded-out position no resistance of significance is sensed. Also, as a consequence of this, the measure of arranging, by means of a simple current limiting circuit, for the electric motor to be switched off when the folded-out position is reached cannot be used without problems anymore.